Add new connbytes match, include a warning (Martin Devera <devik@cdi.cz>)

diff --git a/extensions/.connbytes-test b/extensions/.connbytes-test
new file mode 100755 (executable)
index 0000000..350140f
--- /dev/null
+++ b/extensions/.connbytes-test
@@ -0,0 +1,2 @@
+#! /bin/sh
+[ -f $KERNEL_DIR/net/ipv4/netfilter/ipt_connbytes.c ] && echo connbytes

diff --git a/extensions/libipt_connbytes.c b/extensions/libipt_connbytes.c
new file mode 100644 (file)
index 0000000..abc37be
--- /dev/null
+++ b/extensions/libipt_connbytes.c
@@ -0,0 +1,134 @@
+/* Shared library add-on to iptables to add byte tracking support. */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <iptables.h>
+#include <linux/netfilter_ipv4/ip_conntrack.h>
+#include <linux/netfilter_ipv4/ipt_connbytes.h>
+
+/* Function which prints out usage message. */
+static void
+help(void)
+{
+       printf(
+"connbytes v%s options:\n"
+" [!] --connbytes from:[to]\n"
+"                              Transfered byte range to match\n"
+"\n", IPTABLES_VERSION);
+}
+
+static struct option opts[] = {
+       { "connbytes", 1, 0, '1' },
+       {0}
+};
+
+/* Initialize the match. */
+static void
+init(struct ipt_entry_match *m, unsigned int *nfcache)
+{
+       /* Can't cache this */
+       *nfcache |= NFC_UNKNOWN;
+}
+
+static void
+parse_range(const char *arg, struct ipt_connbytes_info *si)
+{
+       char *colon,*p;
+
+       si->from = strtol(arg,&colon,10);
+       if (*colon != ':') 
+               exit_error(PARAMETER_PROBLEM, "Bad range `%s'", arg);
+       si->to = strtol(colon+1,&p,10);
+       if (p == colon+1) {
+               /* second number omited */
+               si->to = 0xffffffff;
+       }
+       if (si->from > si->to)
+               exit_error(PARAMETER_PROBLEM, "%lu should be less than %lu", si->from,si->to);
+}
+
+/* Function which parses command options; returns true if it
+   ate an option */
+static int
+parse(int c, char **argv, int invert, unsigned int *flags,
+      const struct ipt_entry *entry,
+      unsigned int *nfcache,
+      struct ipt_entry_match **match)
+{
+       struct ipt_connbytes_info *sinfo = (struct ipt_connbytes_info *)(*match)->data;
+       int i;
+
+       switch (c) {
+       case '1':
+               if (check_inverse(optarg, &invert, optind, 0))
+                       optind++;
+
+               parse_range(argv[optind-1], sinfo);
+               if (invert) {
+                       i = sinfo->from;
+                       sinfo->from = sinfo->to;
+                       sinfo->to = i;
+               }
+               *flags = 1;
+               break;
+
+       default:
+               return 0;
+       }
+
+       return 1;
+}
+
+static void final_check(unsigned int flags)
+{
+       if (!flags)
+               exit_error(PARAMETER_PROBLEM, "You must specify `--connbytes'");
+}
+
+/* Prints out the matchinfo. */
+static void
+print(const struct ipt_ip *ip,
+      const struct ipt_entry_match *match,
+      int numeric)
+{
+       struct ipt_connbytes_info *sinfo = (struct ipt_connbytes_info *)match->data;
+
+       if (sinfo->from > sinfo->to) 
+               printf("connbytes ! %lu:%lu",sinfo->to,sinfo->from);
+       else
+               printf("connbytes %lu:%lu",sinfo->from,sinfo->to);
+}
+
+/* Saves the matchinfo in parsable form to stdout. */
+static void save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
+{
+       struct ipt_connbytes_info *sinfo = (struct ipt_connbytes_info *)match->data;
+
+       if (sinfo->from > sinfo->to) 
+               printf("! --connbytes %lu:%lu",sinfo->to,sinfo->from);
+       else
+               printf("--connbytes %lu:%lu",sinfo->from,sinfo->to);
+}
+
+static
+struct iptables_match state
+= { NULL,
+    "connbytes",
+    IPTABLES_VERSION,
+    IPT_ALIGN(sizeof(struct ipt_connbytes_info)),
+    IPT_ALIGN(sizeof(struct ipt_connbytes_info)),
+    &help,
+    &init,
+    &parse,
+    &final_check,
+    &print,
+    &save,
+    opts
+};
+
+void _init(void)
+{
+       register_match(&state);
+}